Open to opportunities

Alexander Omelnitskii

@omelniz

Message

Lead Frontend Engineer specializing in high-performance React architecture and testing.

Serbia

Message

What I'm looking for

I’m looking to lead frontend architecture where React/React Native performance, a strong testing strategy, and streamlined developer workflows drive faster releases and fewer production bugs.

I’m a Lead Frontend Engineer with 12+ years of experience shipping scalable, high-performance React and React Native applications. I focus on frontend architecture, performance optimization, and testing strategy that measurably improves delivery speed and product reliability.

Most recently at Blum, I delivered a multi-chain Web3 trading terminal (Solana, TON, BNB) for 2M+ users, prioritizing high-performance UX and pixel-perfect execution. I also established frontend architecture and engineering practices (Feature-Sliced Design, TypeScript, Storybook, TDD, pair programming), cutting production bugs by 54% and improving code review efficiency by 33%.

Earlier at C14 and Stim, I raised test coverage from 0% to 97%+ and reduced bundle size by up to 50% through codebase analysis, code splitting, and lazy loading. I’ve built contract-first, type-safe API layers (OpenAPI-TS + React-Query), designed auth SDKs on AWS Cognito, and stabilized legacy systems while enabling faster feature delivery.

Experience

Work history, roles, and key accomplishments

Lead Frontend Engineer

Blum

Mar 2025 - Dec 2025 (9 months)

Delivered a multi-chain Web3 trading terminal (Solana, TON, BNB) focused on high-performance, pixel-perfect UX at 2M+ users. Established frontend architecture and built a contract-first, type-safe API layer to improve consistency, speed delivery, and reduce production bugs.

React React Query Vite Vitest TypeScript Storybook TDD React Testing Library Pair Programming Web3 Solana TON BNB

Senior Frontend Engineer

C14

Jun 2023 - Feb 2025 (1 year 8 months)

Established engineering standards including CI/CD, code review workflow, and a TDD process, increasing unit test coverage to 97.81%. Improved performance by reducing bundle size up to 50% and increased conversion by integrating payment options and optimizing checkout funnels using analytics.

React Redux toolkit Redux Saga styled components Vitest React Testing Library CI CD TDD Code Review Lazy Loading CDN Unlimit Google Pay Mixpanel Google Analytics

Senior Frontend Engineer

Stim

Jul 2020 - Apr 2023 (2 years 9 months)

Launched a web version from an existing React Native iOS codebase using React Native for Web, increasing MAU by 23%. Architected CI/CD and AWS-based deployment, stabilized the codebase by improving test coverage, and built an authorization SDK using AWS Cognito.

React Native React Native For Web AWS GraphQL Redux Redux Saga Jest CI CD AWS Lambda Amazon S3 Cloudfront Cognito Authentication Unit Testing Technical Debt Reduction

Senior Frontend Engineer

iPresence

Jul 2018 - Sep 2019 (1 year 2 months)

Implemented pixel-perfect, responsive UI with accessibility (WCAG) and mobile optimizations, delivering new features with 100% unit test coverage. Implemented server-side rendering (SSR), improving initial page load performance by 35% and enhancing Core Web Vitals metrics.

React Redux TDD Redux Saga Responsive Design Accessibility Unit Testing Server Side Rendering Pixel Perfect UI

Senior Frontend Engineer

Thrive Market

Oct 2017 - Apr 2018 (6 months)

Reduced load time by 6x by migrating a Magento-based application to a SPA using the React/Redux stack. Grew subscription conversions by developing an auto-ship page with complex business logic and introduced TDD practices to the team.

React Redux TDD Magento Single Page Applications (SPA)Auto Ship Test Driven Development